1. Field of the Invention
The present invention relates to an electronic component unit such as a system board unit incorporated in a server computer or the like.
2. Description of the Prior Art
A system board unit is incorporated in a server computer, for example. The system board unit includes a printed circuit board or system board. The system board includes central processing unit (CPU) chips mounted on a printed wiring board. A heat sink is received on the individual CPU chip. Airflow runs within the system board unit to cool the CPU chips. A fan is placed in the server computer 11 so as to generate the airflow. The CPU chips are arranged along the direction of the airflow, for example.
The airflow in the server computer absorbs heat from the heat sinks on the CPU chips at upstream positions. The airflow is thus heated. The heated airflow cannot sufficiently absorb heat from the CPU chips at downstream positions. This causes a rise in the temperature of the CPU chips at the downstream positions. The CPU chips at the downstream positions suffer from a reduced processing speed. Since the processing speeds of all the CPU chips are normally set equal, for example, the processing speed of the CPU chips at the upstream positions is leveled down to the processing speed of the CPU chips at the downstream positions.